DISCOVERIES. 161 



Species, in comparison with those of the land, the 

 representations were fewer in this, than in either 

 of the preceding volumes. The colouring and 

 engravings, however, were considered as supe- 

 rior. It contains an account of not less than 

 sixty new species of water-birds, to be met with 

 along the shores and streams of the United 

 States. 



The honour which attaches to these discoveries 

 is considerably enhanced when we consider the 

 peculiar difficulties attending the study of the 

 aquatic species. Through rough and tangled 

 forest tracts, and over dreary pathless plains the 

 land bird must patiently be followed, but the 

 water bird as it sweeps the ocean, or scours the 

 rocks, resorts to retreats which are almost inac- 

 cessible. This Audubon proved, when com- 

 pelled to urge his boat onwards, for miles, perhaps, 

 beneath a burning sun, tormented the while with 

 swarms of insects — to lie on the edge of a preci- 

 pice some hundred feet above the waters, or to 

 crawl along its brink in order to procure a single 

 specimen 1 



American ornithology is rich in the aquatic 

 tribes. Of the heron it contains numerous spe- 

 cies. It possesses also the cormorant, the pelican, 

 the ibis, the curlew, the tern, the petrel, the gull, 

 and others. 



Of the cormorants the double-crested is the 



14* L 



